---
title: reference
framework: IOKit
role: symbol
role_heading: Instance Property
platforms: [iOS 18.4+, iPadOS 18.4+, Mac Catalyst 13.0+, macOS 10.10+, visionOS 2.4+]
path: iokit/osnotificationheader/1455523-reference
---

# reference

## Declaration

```swift
var reference: OSAsyncReference
```